The present invention relates generally to wire harnesses and more particularly to a method and means for securing a wire harness to an interior trim panel of a vehicle.
Current vehicles include many wire harnesses secured to interior trim panels, such as door panels and headliners, for operating interior lights, such as a dome light or lights in a vanity mirror in a visor. Further, interior door trim panels include wire harnesses routed to user activated switches, such as for power windows, power locks, mirrors, etc.
Each wire harness comprises a plurality of wires which are bundled to form a trunk and a plurality of branches extending from the trunk. Typically, each of the branches includes an electrical connector at an outer end. During assembly of the wire harness, the wire bundles are held together in an assembly jig, which includes a plurality of wire supports supporting the wires along each of the main trunk and each of the branches. Each wire is placed onto the assembly jig onto the appropriate wire supports, i.e. from a first branch to the wire harness, along the main trunk and through a second branch, typically at an opposite end of the wire harness. Electrical connectors are then connected to the outer ends of the wires at the branches. The wires are then wrapped with tape along the entire length of the main trunk and each of the branches.
A wire harness is placed on an interior trim panel prior to installation of the trim panel into the vehicle. The main trunk and each of the branches are positioned in appropriate locations on the trim panel. Then, the wire harness is secured to the trim panel with an adhesive, such as a hot glue, which secures the main trunk and branches of the wire harness to the trim panel. This method is time consuming and the adhesive is expensive. Further, it is difficult to secure the wire harness to the trim panel consistently and reliably. Further, manufacture of the wire harness as described above is time consuming and difficult. Wrapping the tape along the entire length of the main trunk and each of the branches is a labor intensive process.
In co-pending application U.S. Ser. No. 08/927,748 filed Sep. 11, 1997, entitled xe2x80x9cWire Harness Foamed to Trim Panel,xe2x80x9d the assignee of which is the assignee of the present invention, a polymer foam sheath encases a plurality of wires and secures the wires to a surface of an interior trim panel. The wires are first routed on the surface of the trim panel. A mold generally comprising a half cylinder forming a trough is placed upon the surface of the trim panel, enclosing the wires within the trough between the mold and the surface of the trim panel. The mold includes troughs matching the main trunk in each of the branches of the wire harness. The foam is then introduced into the trough, thereby encasing the wires and adhering to the trim panel. Although the wire harness formed in this manner performs well, the mold to form the wire harness is cumbersome and large.
The present invention provides a wire harness foamed to an interior trim panel, and a method and device for making the wire harness. The inventive wire harness comprises a plurality of wires routed generally along a surface of a trim panel. The plurality of wires is encased by a polymer and secured to the surface of the trim panel by the polymer.
A foam gun for forming the wire harness generally comprises a wire guide for gathering and aligning the plurality of wires generally adjacent one another and the surface of the interior trim panel. The foam gun further includes a nozzle secured to the guide for delivering the foam. The foam gun further includes a handle mounted to the guide and the nozzle.
According to a method of the present invention, the plurality of wires are first routed on the surface of the trim panel. The foam gun is then placed at a first end of the wires and slid along the surface of the trim panel toward an opposite end of the wires. While the foam gun is moved along the plurality of wires, the foam gun sprays a two-part polymer foam onto the wires. The foam foams and cures, thereby securing the plurality of wires to the trim panel and encasing the plurality of wires. As the foam gun is moved along the plurality of wires, the plurality of wires are gathered together and aligned to be generally adjacent one another and the surface of the trim panel by the wire guide, just before the nozzle sprays the foam onto the wires.